Answer:
CoCl2*6H2O = CoCl2 + 6 H2O
Step-by-step explanation:
Reaction type is decomposition, but this should balance it.
Answer:
a=2
Step-by-step explanation:

In order to get 0, you have to multiple 3 with 0, so that means that 2a-4 has to equal 0.
It's the height of the triangle (the length) times the the width divided by 2.